It's cool that you guys are willing to separate yourselves from the earlier stance of not encouraging any meta, people can still decide in champ select to do something different because I am sure you will not be penalizing people for going against their selected role. This will take a lot of the epic teamwork fails out of the equation plus ensuring people will be playing on their A-game champs/roles.

It actually does not enforce it--leaders of a team will be able to set whatever parameters they want. Double jungle? Five man mid? Make it happen!

But, because team collaboration is the name of the game, your teammates will need to be bought in by queuing for that position and accepting the plan beforehand. It's built into the system to allow for flexible meta expression.

Kind of, but not really. You can still pick any champ you want to play "mid". The only thing this really stops is people going 2 mid/ 2 jungle. Which never really works in solo queue unless it is actually a team that queued together and has cooperation to play that way. Which if you are a team queuing together i'm sure riot will probably think of work-arounds so you could do this if you wanted.